Keyway cutting tool



Nov. 2 5 194.1. D. CURRIE KEYWAY CUTTING TOOL Filed June 7, 1940 mi wPatented Nov. 25, 1941 entree sraras raftercarrier E WAY cur ew 790.

Dug ald Currie DesMoine s Iowa. Application J iled, 1940,; Serial i t,-339,332 3 Claims. (01. 90-40) The object of my invention is to provide ahand-operated keyway cutting tool for cutting keyways in round shafts atthe ends thereof, which tool is of simple, durable and inexpensiveconstruction.

- More specifically, it is my object to provide a tool of this class inwhich shafts of different diameters may be readily, quickly and easilyclamped and firmly held with the longitudinal axes of the'shaftexactlyin line with the path of travel of the cutting tool, whereby thekeyway formed by the tool will be exactly parallel with the longitudinalaxis of the shaft, and further to provide a tool of this class in Whichthe manual power applied in the operation of the tool will necessarilybe applied insuch manner as to form the side walls of the keyway exactlyparallel to thelongitudinal axis of the shaft being cut, to therebyavoid distortion of said side 'walls as is commonly done withkeywaycutters' now in commen use, in which the manual powerapplied foroperating the tool is frequently applied in such manner as to laterallydeflect the cutting tool during its cutting stroke and thereby formingside walls of the keyway along lines divergent from true parallelismwith the longitudinalaxis of'the shaft.

In the accompanying drawing- Figure 1 shows a side elevation of myimproved keyway cutter applied to a shaft, parts being '3' broken awayto show certain structural details;

Figure 2 shows a vertical sectional view on the line 22 of Figure 1;

Figure 3 shows an end elevation looking toward the end at which thecutting tool is located;

Figure 4 shows a horizontal sectional view on the line 4-4 of Figure 1;

Figure 5 shows a detail perspective view of the cutter blade and a part.of the blade holder in which the blade is slidingly mounted; and

Figure 6 shows a detail sectional view on the line 6-6 of Figure 1.

The reference numeral It indicates the body portion of the tool whichserves as a support for the entire tool. a centrally arrangedlongitudinal opening I I at its lower portion, of a size to freelyreceive the largest shafts for which the tool is adapted; the upper wallforming this opening has its sides tapered inwardly and upwardly at I2along lines parallel with the longitudinal axis of the body. Set screwsI3 are extended through the lower portion of the body It into theopening It to engage the under central portion of a shaft in the This yportion is formed with opening. When these set screws are forced firmly55 the body It.-

against a shaft I4 the shaft is thereby forced against the tapered wallsl2 and thereby moved to position exactly parallel with the longitudinalaxis of the body, and there firmly held.

Directly above the opening II is a'longitudinal opening I5 centeredrelative to the shaft opening and of rectangular formation. Slidinglymounted within the opening is the cuttingtool supporting bar It, capableof longitudinal movement only and so ac'curat'elyfitted as to preventlateral movement. At one end of the bar I fi'is ah integral upwardextension IT.

The "tool-carrying frame comprises two side members I8 overlapping thesideof the extension I I and pivotally connected therewith by the pivotpin IBat its top portion. The body portion I9 of this frame is extendedacross the front of the extension I], and is forme'd'with a taperedgroove at its front central portion, in line longitu-' dinally with thelongitudinal center of the bar I6. In this groove 20 there is slidinglymounted a tool holder 2| tapered to fitthe groove and having an'openingto receive the cutting tool 22. The side edgesof the tool and holder aretapered to prevent forward'movement of the tool relativeto theholdei." Atool guiding plate 23 is secured to the front of the body portion I9 bybolts 24. At the upper end of the plate 23 is a rearward extension 25 inwhich is mounted a feed screw 26 to engage the upper end of the tool 22.A winged set screw 21 is mounted in the central portion of the body I 9for clamping the tool in various positions of its adjustment.

At the rear end of the bar I 6 there is a rectangular extension 28, ofreduced size, extended through an upright 29 which has a rectangularopening accurately fitting the extension. This upright is fixed to thebar I6 by a nut 30 on the rear of the extension.

Fulcrumed to the body Iil is a lever 3I accurately centered verticallyabove the longitudinal center of the shaft opening and movable forwardlyand rearwardly. A link 32 connects the lever 3| with the upright 29.

Resting on top of the bar ing in the body set screws 32 I6 within theopen- IE are two bearing plates BI, and

are extended through the top of to engage said bearing plates. Inpractice, I adjust said screws 32 to firmly engage the bar It, but notfirmly enough to prevent longitudinal movement of the bar I6, therebyavoiding a chattering action which would occur if the bars It werepermitted to move up and down in the body I I3.

In practical use a shaft of any desired diameter is placed in theopening II, and the set screws l3 are drawn up to firmly press the shaftagainst the tapered upper walls of the opening. This operation willautomatically center the shaft and firmly hold it against bothlongitudinal and lateral movement. It is not necessary for the operatorto exercise any skill in operating these set screws because they cannotfunction in any way to avoid the desired accurate centering of theshaft. Then a keyway cutting tool of the proper size for cutting thedesired keyway is applied and firmly clamped, and then all that theoperator need do is to reciprocate the lever 3|. Due to the fact thatthe tool-carrying guide bar is close to and parallel with the shaftbeing operated on, the cutter tool will not chatter-during the cuttingstroke as is sometimes the case when the tool-carrying bar is widelyspaced apart from the shaft, and due to the fact that the operatinglever is centered directly above the longitudinal center of the shaftbeing operated on and movable only in a direction parallel with theshaft, all motion applied to the lever operates to move the'cutter toolin a straight line, hence, all lateral distortion of the keyway isavoided.

I claim as my invention:

1. A keyway cutting tool, comprising a body portion formed with twolongitudinal openings, one being close to and directly above the otherwith their longitudinal centers in vertical alignment, the upper wall ofthe body at the lower opening being inclined from its side edgesupwardly and inwardly, and the upper opening being rectangular inoutline, set screws extended through the bottom of the body to engage ashaft in the lower opening and force it to centered position againstsaid inclined wall, a tool-carrying bar in said upper opening,rectangular in section and slidingly mounted thereon, a cutting toolpivoted to one end of said bar in line vertically with the longitudinalcenter of the said lower opening, an upright fixed to the other end ofsaid bar, a link pivoted thereto, a lever fulcrumed to the upper part ofsaid body in line vertically with the longitudinal centers of saidopenings and pivoted to said link and movable longitudinally of saidbar.

2. A keyway cutting tool, comprising a body portion formed with twolongitudinal openings, one being close to and directly above the otherwith their longitudinal centers in vertical alignment, the upper wall ofthe body at the lower opening being inclined from its side edgesupwardly and inwardly, and the upper opening being rectangular inoutline, set screws extended through the bottom of the body to engage ashaft in the lower opening and force it to centered position againstsaid inclined wall, a tool-carrying bar in said upper opening,rectangular in section and slidingly mounted thereon, an upright fixedto one end of the bar, a tool-carrying member pivoted thereto above thelongitudinal center of the bar, a keyway cutter tool adjustably fixed tosaid tool-carrying member, an upright fixed to the other end of saidbar, a link pivoted thereto, a lever fulcrumed to the upper part of saidbody in line vertically with the longitudinal centers of said openingsand pivoted to said link and movable longitudinally of said bar.

3. A keyway cutting tool, comprising a rigid body portion formed with alongitudinally arranged opening to receive a shaft, the wall of saidopening at the top being inclined inwardly and upwardly toward alongitudinal central line, means carried by the body portion forengaging a shaft in said opening and for forcing it upwardly againstsaid inclined wall and thereby moving it to longitudinally centeredposition and fixing it in said position, said rigid body having a secondlongitudinal opening above the first, a tool-carrying bar slidinglymounted in the sec ond opening and centered above the center of theshaft opening, the tool carrying bar and its opening being of irregularoutline and closely fitted to thereby prevent rotary movement of thetool-carrying bar, a lever fulcrumed to the body in line vertically withthe longitudinal centers of the said openings, and a link pivoted to thelever and to the tool-carrying bar.

DUGALD CURRIE.

